In Painful News for Tour, Serena Williams Ends Her Season

Serena Williams’s great and strange season came to an apparent end on Thursday when she announced that she would not play in the China Open in Beijing next week or the WTA Finals in Singapore later this month.

In a statement, Williams, who turned 34 on Saturday, cited a need to recover from injuries that had troubled her during the year but did not keep her from winning five titles, including three major tournaments, and compiling a 53-3 record.

She also cited the emotional pain of failing to complete the Grand Slam last month at the United States Open.

“It’s no secret I’ve played injured most of the year — whether it was my elbow, my knee or, in the final moments after a certain match in Flushing, my heart,” she said in the statement, referring to the U.S. Open site.

Her semifinal loss to Roberta Vinci, an effervescent and unseeded Italian veteran, was one of the biggest surprises in the sport’s long history. And unless Williams changes her mind and decides to support the women’s tour by playing in Singapore, the Vinci upset will serve as the unexpectedly downbeat closing note to a season in which Williams managed to fend off tennis trouble again and again and become a true global focal point as she chased the Grand Slam.

Her decision to call it a season is understandable if she is dealing with significant injuries. She was seen favoring her right elbow during training at the Open. She has made it back to the No. 1 ranking after conquering much more serious health concerns and is well aware of her limits at this stage of her career. She retired from three tournaments this year, citing injuries.

But Williams’s calling time on her season would be much less understandable if it were primarily about lingering disappointment or faltering motivation, which was what her coach, Patrick Mouratoglou, seemed to suggest this week.

“I don’t doubt she will have the motivation to win more Grand Slams and reach records,” Mouratoglou told ESPNW. “I’m just thinking about the end of the season, and I don’t know how high the motivation is, and I don’t think she should go play competitions if her motivation is not high enough.”

He added: “She was two matches away from something really big, so it was very painful. Any loss is very painful for her, but this one even more than usual, so it just takes time to recover from it. When the motivation comes back, which I don’t doubt it will, then it will be time to start tournaments again.”

Whatever the primary cause — and determining primary cause can be a challenge with Williams — her decision, which she termed “very difficult,” is a major blow to the tour.

“To have the tour finals happening without your best player by far and biggest superstar is really too bad,” said Pam Shriver, a former president of the WTA Tour Players Association who is now a television analyst.

Asia has been the focal point of the WTA’s growth strategy in recent years. The China Open is one of just four premier mandatory events on the circuit, and the WTA Finals are the tour’s most important event, in both financial and competitive terms. (The four Grand Slam tournaments are independent entities.)

The WTA Finals, an elite season-ending event, bring together the top eight singles players and top eight doubles teams. Singapore is in the second year of a five-year deal to stage the tournament, a deal that is worth in excess of $70 million.

When Singapore signed on in 2013, the event’s three primary attractions figured to be Williams, Maria Sharapova and the Chinese star Li Na. But Li has retired, and Sharapova is uncertain to play in the finals after withdrawing from the China Open with a forearm injury incurred in Wuhan, where she retired during her first match since Wimbledon.

Now Williams is out after winning the title in Singapore last year.

When the British star Andy Murray suggested he might opt out of the men’s version of the event, the ATP World Tour Finals in London, to save himself for the Davis Cup final this year, the ATP chief Chris Kermode quickly issued a statement emphasizing that the World Tour Finals were a mandatory event.

There was no such statement from the WTA on Thursday, even though the WTA Finals, like the China Open, are a mandatory event.

“Serena’s health has to be her No. 1 priority,” Micky Lawler, the WTA president, said in a statement. “The risk of injury is a reality in the world of elite athletic performance.”

Stacey Allaster, the WTA chief executive officer who negotiated the Singapore deal, might have persuaded Williams to delay her decision in a different context. But Allaster has announced her resignation, and her last day on official duty is Friday, which will leave Lawler as the highest-ranking WTA official for now.

Williams’s withdrawals are not without consequence. By missing Beijing, she will forfeit the $450,000 bonus that goes to a No. 1 player who participates in all four premier mandatory events. She could also be fined and even suspended if she fails to compensate for her withdrawal by doing promotional work for the WTA Tour Finals.

WTA officials still hope she will make an appearance in Singapore at this year’s event even if she does not play. But the awkward possibility for the WTA is that she could play in Asia later this year — not in an official event, but in the big-money International Premier Tennis League, in which she has signed to play for the Manila Mavericks.

Singapore has a franchise in that league.

“I plan to return to practicing and participating in exhibition matches later this year,” Williams said in her statement. “And when I do, I will focus and focus and focus, so I can continue my journey in this beautiful game.”

Her 2015 season — which will be remembered for major achievement and one crushing defeat — was quite a journey all by itself.

A version of this article appears in print on , Section B, Page 11 of the New York edition with the headline: Williams Is Hurting. Now, So Is the Tour. . Order Reprints | Today’s Paper | Subscribe